Technical Overview of Modern Optics Systems

Optics systems are some of the most popular after-market accessories for rifles and pistols, but there is no other area of firearm equipment that is so full of jargon.

If you are new to optical systems for guns, or if you are an old pro who needs some reminders, I’m here to help. Choosing an optical system for your weapon can be a complicated business, because the type of sight you need will depend not only on your weapon, but in the types of situation you are going to use it in.

Today, I’ll take you through everything you should consider when choosing an optics system.

The Basics

Let’s start with the basics. There are essentially two different types of firearm optics, whether you are shooting a rifle, a pistol, or even an air gun.

The first is the telescopic sight. These are commonly known as ‘scopes’, and are the type of optics system you are probably most familiar with from war movies. They work a bit like a telescope, as the name would suggest – a series of lenses is used to to magnify the image through the sight, which allows you to make a precision shot.

The other main type of gun optics is the reflex sight. These do no magnify the image through the sight. They usually feature a single point of reference, such as a red-dot, which makes target acquisition extremely fast. This type of sight is generally used for close-quarter combat, or when a large number of targets need to be engaged. They are not commonly used for long-range shooting, although experienced users can get pretty good at hitting targets at range with this type of sight.

The Jargon Explained

Beyond the basic choice between telescopic and reflex sights, you have a huge range of options when it comes to the technical specifications of your sight. Unfortunately, a lot of these options are expressed in complicated, obscure jargon. Let’s take a look at some of the key terms:

Magnification – This is pretty straightforward, but can be difficult to work out unless you know what the numbers mean. Most telescopic sights will give a magnification level, for instance as “1.25-4”. This means that the scope offers a range of magnification from x1.25 to x4.

Exit Pupil – The exit pupil is basically the amount of light that enters the scope. A larger exit pupil (which is the size of the hole at the target end of the scope) will allow more light into the scope. This can be really useful when shooting in low light conditions.

Eye Relief – This is a big more technical, but is basically the distance from which you can see the entire image in the scope. Scopes are not designed to be looked through when they are right up against your eye, but rather from a small distance away. One of the most common mistakes when setting up a scope is not to take into account the eye relief distance, which can make the scope appear dark, or limit your field of view.

Field of View – This is the width of what you can see through the scope. It’s generally measures in feet at specific distances. There is a compromise to be made in this area, because in general the higher the magnification of a scope, the narrower the field of view.

Minute of Angle – The minute of angle (or MOA, as it is commonly called) is a measurement of accuracy, essentially. 1 MOA is equivalent to 1/60th of a degree, and is equivalent to pretty much 1 inch at 100 yards. Whilst shooting, a deviation of 1 MOA means you will get all your shots within a 1-inch diameter circle at 100 yards.

Reticle – This is the fancy name for the aiming indicator inside the scope. It can be the point on an old-type iron sight, a red dot, a red ring, a horseshoe, or any number of different shapes. Which of these you go for depends on what you are use to, and the type of shooting you are going to be doing. Sights for most popular rifles, for instance the AR-15, can be bought with a variety of different reticle types.

Setting Up Your Optics

Once you’ve decided on an optics system, you need to set it up correctly in order for it to work properly. The most important element here is zeroing the sight for a particular distance. Since the sight and the barrel of your gun are not totally in-line, the reticle in your sight will only be accurate at a specific distance. Which distance you choose will depend on what you are shooting at, and at what distance.

Once you’ve set up your scope, don’t let anyone mess around with it. After a bit of practice, you should be able to work out how high or low your shots will strike the target at specific distances, and messing around with your scope will ultimately lead to confusion. Pick a distance, zero your sights, and then learn to work around them.

Be Prepared

Be aware that, no matter how expensive and advanced your optical system is, any system can fail at the critical moment. If you are out hunting, and knock your scope out of alignment on a tree, you need to know how to shoot without it.

For this reason, don’t just rely on your ability to shoot through your scope. Practice with the iron sights on your rifle as well. Whilst shooting through iron sights can be difficult, being able to shoot without a scope will ultimately make you a better shooter.

Practice, Practice, Practice

Don’t assume that getting a high-tech sight will automatically make you a more accurate shooter. As with everything else when it comes to shooting, the key is to know your equipment inside out, and this involves practice.

Every sight, no matter how advanced an expensive, will have its own peculiarities, and knowing what these are is much more important that the type of sight you use.